The present invention relates to a method and apparatus for separating gaseous or vaporous substances having different molecular weights and/or different gas kinetically effective cross sections, wherein the mixture to be separated is conducted through a nozzle into a separating chamber where it is deflected, whereupon one or a plurality of separating baffles, which protrude into the flow path, collect partial streams of different compositions which are then discharged separately.
The principle of the separating nozzle method is disclosed in German Pat. No. 1,052,955 and is based on the partial spatial separation of a jet expanding from a nozzle-like opening into a chamber at subatmospheric pressure. German Pat. Nos. 1,096,875 and 1,198,328 show that the economy of a process for separating isotopes of heavy elements can be improved by the use of a light additive gas.
From theoretical investigations and experimental tests, it is known that a high separating effect can be realized only if the velocity ratio is as high as possible and at the same time the deflection angle of the flow lines of the jet is as large as possible. The velocity ratio is the ratio of flow velocity to most probable thermal velocity. The most probable thermal velocity c is defined by the equation EQU c=.sqroot.2 k T/m
where k is the Boltemann constant, T is the absolute temperature and m is the molecular weight.